Linear chloromethylmethylsiloxanes



Patented May 9, 1950 2,507,316 orFlcE LINEAR oHLoRoMETHYLMEIHYL. SILOXqANESF RohRoy McGregor, Verona, and" Earl Leatheni' Warrick, Pittsburgh, Pa:, Corning Corporation, notation of Michigan assignors: to; Dom

Midlands. Mich, 001".

No Drawing. Application July 19, 1948, Serial No. 39,594

The; present invention ,-r elates-.-to; (chloromethgr yDmethylpclysiloxanes and to their production.

Siloxanes which have active functional groups bonded to the silicon atoms of the siloxane would be of substantial importance inasmuch as the provision of such siloxanes would make possible the preparation of a wide range of derivatives from the siloxanes in question.

Objects of the present invention are the provision of siloxanes having such active functional substituents linked to the silicon atoms by carbon to silicon bonds.

Compounds in accordance herewith correspond to the general formula R3S10(S1R20)$S1R3. In this general type of compound, :2 has a positive value, and each R. is selected from the group methyl and chloromethyl, there being both methyl and chloromethyl radicals contained in the compound but not more than one chloromethyl radical linked to any one silicon atom.

Compounds of this type may be prepared by cocondensing chloromethylmethylsiloxane units with either trimethylsiloxane units or chloromethyldimethylsiloxane units. Likewise, compounds in accordance herewith may be prepared by cocondensing dimethylsiloxane units with chloromethyldim'ethylsiloxane units. Operatively, the condensates may be prepared by cohydrolyzing and cocondensing dimethyldichlorosilane or chloromethylmethyldichlorosilane with trimethylchlorosilane or chloromethyldimethylchlorosilane. Alternatively, the compounds hereof may be produced by equilibration of the corresponding siloxanes.

The products hereof are useful per se as dielectric fluids. They are further of considerable utility as siloxan e' forthe produc tion of compounds oftypes which it has been impossible otherwise to prepare.

EXAll/[PLE 1 A solution of 178 grams of chloromethyldimethylchlorosilane in aqueous ethanol was refluxed for two hours with 46 grams of crystalline hexa- 'methylcyclotrisiloxane. The product of hydrolysis and rearrangement was washed with water until the wash water was neutral to litm'us, dried over calcium chloride and finally distilled. The properties of the products so obtained are shown in Series No. 1 in the table following Example 3.

EXAMPLE 2 A solution containing one gram mol of hexamethyldisiloxane in aqueous methanol was refluxed with one gram mol of chloromethylmethyldichlorosilane for 3.5 hours. The products were washed with water until the wash water was neutral to litmus, following which the product was dried over calcium chloride, and finally distilled. The products were obtained which are shown in Series No. 2 of the table following Example 3.

EXAMPLE 3 B. P., 0. D

SERIES NO. I-CICHzSl'MezO (MezSiOhSiMezCHzCl Cs Viscosity Dielectric E (Viscy constant 0.

4. 0. 99s a, 068 5. 61 1. 204 3,112 6. so 1. 413 a, 17s ""if 'ii'i'sls'ily'"' IIIIIIIIII SE RIE S N O. II-MeaSiO (MeSl'OHzC10),SiMe;

2. 46 0. 697 2, 221 3. 9 269. 8 6. 02 1. 3, 286 5. l 77 189. 5 9. 85 1. 673 3, 584 5. 4 85 164. 2 21.17 2. 680 4, 198 5. 8 77 152. 6 high vislcosity z 1 SERIES N0. III-CIGHgMea-SiO(M8SiOHzCIO),SiMe:CH7Cl Mal. (56.8" 0.) Weight 1 E8: E0 111111)): 175.5 1. 4465 1. 1115 81.83 2. 747 1. 443 3,586 7. 3 341 a min. 2 167 1. 1574 104. 44 4. 969 2. 446 3, 958 7. 1 440 3 1.1819 128.17 7. 999 3. 613 4. 429 6. 8 560 1 high viscosity E 1 E(Vlsc.) =Energy of activation of flow in calories as determined by the equation E(Visc.)=2.3 R log Bi the viscosity at temperature T1, m is the viscosity at temperature T, and R is the gas constant in calories per degree.

That which is claimed is:

1. Compounds in accordance with the general formula R(CH3)2SiO[SiRCH30]ISi(CH3) 2B in which a: has a positive value, R selected from the group consisting of methyl and chloromethyl radicals in which compounds both Rs are alike in any one molecule and R is selected from the group consisting of methyl and chloromethyl radicals, there being at least one chloromethyl radical in each molecule.

2. C1CH2 (CH3) 2SiO[Si(CI-I3) 2O] =Si(CHz) zcHzCl in which a: has a positive value.

3. (CH3) 3Si0 (SiCHzCI-IaClO) Si(CH3) s in which a: has a positive value.

C1CH2(CH3) 2Si0 (SiCHaCHzClO) ZSi-(CHZ) 2011201 in which a: has a positive value.

ROB ROY McGREGOR.

EARL LEATHEN WAR-RICK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,384,384 McGregor (2) Sept. 4, 1945 2,435,148 McGregor (1) Jan. 27, 1948 15 2,439,669 Nordlander Apr. 13. 1943 

1. COMPOUNDS IN ACCORDANCE WITH THE GENERAL FORMULA R(CH3) 2SIO(SIR''CH30)XSI(CH3)2R IN WHICH X HAS A POSITIVE VALURE, R IS SELECTED FROM THE GROUP CONSISTING OF METHYL AND CHLOROMETHYL RADICALS IN WHICH CCOMPOUNDS BOTH R''S ARE ALIKE IN ANY ONE MOLECULE AND R'' IS SELECTED FROM THE GROUP CONSISTING OF METHYL AND CHLOROMETHYL RADICALS, THERE BEING AT LEAST ONE CHLOROMETHYL RADICAL IN EACH MOLECULE. 